Twitter looks to move into mainstream

At its first Chirp conference, the firm reports rapid growth and tries to reassure developers alarmed by the announcement of new advertising initiatives.

Reporting from San Francisco — Twitter Inc., the fast-growing social network, said Wednesday that it has more than 105 million registered users, up more than 1,500% from a year ago, and is adding 300,000 users every day.

The staggering figures were unveiled by Biz Stone and Evan Williams, co-founders of the 4-year-old Internet company, at its inaugural developers conference, dubbed Chirp.

In addition to an explosion of users, Twitter is fielding 600 million search queries each day and users are sending out 55 million tweets a day, they said. Tweets are short messages of 140 characters or fewer.

San Francisco-based Twitter has evolved from a crude sketch on a piece of paper in 2006 to a breakaway pop-culture phenomenon (Ashton Kutcher's race against CNN for 1 million followers on Twitter) and crucial political force (unrest in Iran prompted the State Department to ask Twitter to cancel a planned outage).

"The open exchange of information has a positive impact on the world," Williams said.

Now the company is trying to figure out how to catapult Twitter into the mainstream by making it easier for people to sign up and use it. Williams said that when someone starts to type "I don't get . . . " into a Google search, the No. 2 suggestion is "I don't get Twitter," right after "I don't get drunk I get awesome."

That's at the heart of the dilemma facing Twitter and its developers. "When we did the research we found that we were really under-serving users," Williams said. "We're not getting nearly as many users started and engaged."

Both tried to soften the blow of a series of moves by the company in the last week (announcing official mobile applications and rolling out an advertising strategy) that have alarmed developers, who have given Twitter a huge boost by building features and applications that make the service easier to use and more addictive.

"You guys have not only made Twitter better, you've helped shape it," Williams said. "You've helped define what it is for us and millions of users."

The company also made a couple of significant announcements. Internet search giant Google Inc. and the Library of Congress plan to index Twitter's massive archive.

And Twitter is introducing a feature called "Points of Interest," which will allow people to see all the tweets emanating from a particular spot. Williams said the feature was not intended to compete with geolocation services.

"Revenue is happening at Twitter this year," Williams said. He told developers: "It's not just about us, but it's about you if you choose to participate in that."